"You really want somebody who's coming for the right reasons," Mayer told Gelles. "To get the people who are really aligned with the mission, you want to make sure that they're fairly compensated, but not necessarily motivated by that compensation."

Hence the "meet, not beat" tactic, which Mayer said she used at both Google and Yahoo. Presumably, that means she'd pay them relative to similar companies, but not so much more than they'd get elsewhere.

"It's the trade-off between mercenaries and missionaries," Mayer said.

In a report by Business Insider's Rachel Gillett on how Google determines compensation, she pointed to a Quora answer by Bob See, who was a principal recruiter for Google Engineering from 2005 to 2014, saying that Google generally doesn't negotiate compensation packages with candidates but that it could revise their offer if the employee brings a competing one to the table.

It's also worth noting that according to PayScale data, Google's salaries are higher than those at most other tech companies — at Google, the median pay for an early-career employee is $106,900, and for a mid-career employee it's $151,600. (Yahoo isn't among the 18 highest-paying tech companies, according to PayScale.)

Other tech companies have similar stances on salary negotiation. Janelle Gale, Facebook's vice president of human resources, told Business Insider's Aine Cain, "We don't want to get into a negotiation, because that basically means whoever is the best negotiator wins."

Gale added: "We're not hiring you for your negotiation skills, unless you are in a negotiation role, like business development."